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1.
The distribution of three chromosome races (Moscow, Western Dvina, and Seliger) of the common shrew Sorex araneus L. in the zone of contact between their ranges in the Valdai Heights (32°00′ E, 57°00′ N) is discussed. The area co-inhabited by all the three races is extremely small. Representatives of all the three races have been captured on only one trap line, although there are no obstacles to the expansion of shrews. The extremely small area co-inhabited by the three races, as well as the strictly parapatric distribution of the Moscow and Western Dvina races, may be related with competition forms such as avoidance of contacts and separation of ecological niches.  相似文献   
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The structural-temporal organization of a murine rodent community in the taiga has been studied near Lake Teletskoe, Mountain Altai. The results show that the long-term dynamics of indices characterizing community diversity depend mainly on changes in the structure of dominance rather than on the population dynamics of species. The distribution of species in the factor space corresponds to their preference for certain biotopes, from dry to relatively moist. An analysis of relationships within the rodent community has revealed the synchronous dynamics of species abundance and antiphase pattern of changes in the structural indices of dominant species.  相似文献   
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Environmental Science and Pollution Research - This study aims to assess interrelationships between serum lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg) concentrations in pregnant women in...  相似文献   
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A number of different approaches have been used to explain the successes and failures of biodiversity conservation strategies in developing countries. However, to date, little attention has been paid toward assessing the influence of knowledge transfer between science, policy, and conservation practices in the implementation of these strategies. Vietnam’s Pu Luong Cuc Phuong Conservation Area is a globally important ecosystem, situated within a limestone landscape and inhabited by hundreds of local communities. Biodiversity conservation has become an important part of sustainable development in this area. This study analyzes three conservation strategies employed in the Pu Luong Cuc Phuong Conservation Area by applying the Research–Integration–Utilization (RIU) model of scientific knowledge transfer. Our analyses reveal weaknesses in scientific knowledge transfer arising from low-quality research and poor integration strategies. Based on our results, we developed recommendations to improve research and integration in an effort to enhance science-based policy support.  相似文献   
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Temporal variation is one of the least known components of defence production in marine organisms. Here we examined whether there is a predictable temporal pattern in the production of chemical and structural defences by a marine invertebrate. To assess the seasonal variation in chemical defence, we measured ascididemin, the main pyridoacridine alkaloid in the blue Mediterranean morph of the ascidian Cystodytes sp. Structural defence variability was assessed on the basis of colony ash content, as it contains mainly spicules. Ascididemin concentration and the colony ash content displayed an annual cycle, reaching a minimum in spring and peaking in summer. Cross-correlation analyses with existing data on growth and reproduction suggested a significant trade-off between investment in reproduction and the other biological parameters considered (growth, inorganic content and ascididemin concentration). Our results suggest that optimization of resource allocation, probably influenced by biotic interactions and physical factors, shaped the temporal trends observed in secondary metabolite concentration and inorganic content.  相似文献   
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As part of the Russian FIRE BEAR (Fire Effects in the Boreal Eurasia Region) Project, replicated 4-ha experimental fires were conducted on a dry Scotch pine (Pinus sylvestris)/lichen (Cladonia sp.)/feathermoss (Pleurozeum schreberi) forest site in central Siberia. Observations from the initial seven surface fires (2000-2001) ignited under a range of burning conditions quantified the different fuel consumption and fire behavior characteristics (e.g., rate of spread, fireline intensity, etc.) possible in this particular forest fuel type. Experimental results and dendrochronological study of local fire history both support the dominance of local fire regimes by low to moderate-intensity surface fires. Carbon released by the experimental fires ranged from 4.8 to 15.4 t C ha− 1 depending on fuel conditions and fire severity. Preliminary emission data show a strong correlation between carbon dioxide (CO2) and carbon monoxide (CO) emissions, which should facilitate accurate estimates of fire impacts on atmospheric chemistry. Carbon concentration in smoke samples was related to fire severity. The short landscape-scale fire-return interval (50 years), combined with typically low fire severity, in pine ecosystems of central Siberia is often associated with low tree mortality and relatively rapid buildup of litter and understory fuels after a fire.  相似文献   
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The geographic variation of the water vole Arvicola terrestris L. has been analyzed with respect to two linear combinations of craniometric characters with the highest additive heritability (h 2 = 0.59 and h 2 = 0.52). The greatest differences have been revealed between the territorially close montane and piedmont populations. The lowland and montane populations have proved to differ to the smallest extent, despite their spatial and altitudinal separation. Selection under extreme conditions that leads to similar phenotypic results may be based on the common genetic background of these populations, irrespective of considerable distances between them and different environmental conditions in their habitats.  相似文献   
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The main objective of this work was to investigate the temporal variability of hydrochemical parameters in two coastal regions of the Northeastern Black Sea: the Gelendzhik bay, influenced by anthropogenic activities and the Golubaya bay an open coastal region. Dissolved oxygen, biochemical oxygen demand, pH, alkalinity, phosphate, organic phosphorus, silicates, nitrates, nitrites, ammonia, organic nitrogen, oil products and heavy metals were measured. Si/P and Si/N ratios showed that the Gelendzhik bay waters were significantly enriched in nitrogen and phosphorus compounds. Unlike the Golubaya bay, phosphates were always present in the Gelendzhik bay, and development of photo-synthesis was not limited by these. Features of seasonal variability of nutrients in the Gelendzhik bay (increased concentrations and pronounced summer-autumn maximum) appeared to be a result of human impact—outflow of nutrients with shore input and recreational activities during the summer holiday season. The data obtained indicate that pollution from local spots from the coast of the Black Sea, related primarily to eutrophication, could play a large role in the nutrient balance of the sea and could affect its ecological state.  相似文献   
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